COSMIC PHILOSOPHY 



or as vertebrates and mollusks. In other words 

 natural selection, acting upon such fortuitous 

 individual variations, would tend to produce 

 indefinitely increasing differentiations in many 

 directions. Such differentiations are to be seen 

 in the amazingly elaborate contrivances for the 

 fertilization of orchids, the explanation of which 

 is one of Mr. Darwin's most brilliant achieve- 

 ments. But when it is admitted that a great 

 number of similar adaptive variations must be 

 simultaneously occurring in the same direction, 

 then it is obvious that the natural selection of 

 such variations may often produce analogous 

 results in different genera and families, or even 

 in different orders, classes, or sub-kingdoms. 

 Mr. Mivart alleges the many resemblances be- 

 tween whales and the ancient ichthyosaurians 

 as hardly explicable on the theory of the selec- 

 tion of fortuitous variations. But when we 

 recollect that the vertebrate structure of mam- 

 mals is at the outset homologous with that of 

 reptiles, and that direct adaptation must of it- 

 self tend to produce similar variations alike in 

 mammals and in reptiles which pass from a 

 terrestrial into an aquatic environment, the re- 

 semblance between a whale and an ichthyosaurus 

 ceases to be an enigma. The superficial resem- 

 blance of a whale to a fish is a fact of like na- 

 ture. And in the case of amphibious carnivora, 

 like the seal, direct adaptation to a partially 



84 



